The present invention relates generally to data processing systems and, more particularly, to the discoverability and navigation of hyperlinks within a hypertext document using tabs.
Usage of the Internet has increased dramatically in the last few years. Most users of the Internet access web pages that are stored at web sites. The web pages are typically hypertext documents that are downloaded from an Internet server to a client computer system. These hypertext documents are encoded in the hypertext markup language (HTML). HTML is a simple markup language that enables the development of hypertext documents that are platform independent.
HTML documents follow a particular syntax. An example document is helpful to illustrate this syntax.
 less than !DOCTYPE HTML PUBLIC xe2x80x9cxe2x80x94//IETF//DTD HTML 2.0//ENxe2x80x9d greater than 
 less than HTML greater than 
 less than !xe2x80x94xe2x80x94Here""s a good place to put a comment.xe2x80x94xe2x80x94 greater than 
 less than HEAD greater than 
 less than TITLE greater than Structural Example less than /TITLE greater than 
 less than /HEAD greater than  less than BODY greater than 
 less than H1 greater than First Header less than /H1 greater than 
 less than P greater than This is a paragraph in the example HTML file. Keep in mind that the title does not appear in the document text, but that the header (defined by H1).does. less than /P greater than 
 less than OL greater than 
 less than L1 greater than First item in an ordered list.
 less than LI greater than Second item in an ordered list.
 less than UL COMPACT greater than 
 less than LI greater than Note that lists can be nested;
 less than LI greater than Whitespace may be used to assist in reading the HTML source.
 less than /UL greater than 
 less than LI greater than Third item in an ordered list.
 less than /OL greater than 
 less than P greater than This is an additional paragraph. Technically, end tags are not required for paragraphs, although they are allowed. You can include character highlighting in a paragraph.  less than EM greater than This sentence of the paragraph is emphasized.  less than /EM greater than Note that the andlt:/Pandgt: end tag has been omitted.
 less than P greater than 
 less than IMG SRC=xe2x80x9ctriangle.xbmxe2x80x9d alt=xe2x80x9cWarning: xe2x80x9d greater than 
Be sure to read these  less than b greater than bold instructions less than /b greater than .
 less than /BODY greater than  less than /HTML greater than 
As can be seen in the above example, hypertext documents typically contain a number of tags. The tags are delimited by xe2x80x9c less than xe2x80x9d and xe2x80x9c greater than .xe2x80x9d Tags delimit elements such as headings, paragraphs, lists, character highlighting and links. Most HTML elements are identified in the document by a start tag, which gives the element name and attributes, followed by the content, which in turn is followed by an end tag. Start tags are delimited by xe2x80x9c less than xe2x80x9d and xe2x80x9c greater than ,xe2x80x9d whereas end tags are delimited by xe2x80x9c less than /xe2x80x9d and xe2x80x9c greater than .xe2x80x9d An example of a start tag in the above example document is xe2x80x9c less than H1 greater than xe2x80x9d and an example of an end tag is xe2x80x9c less than /H1 greater than .xe2x80x9d In the above example document, the tags used to delimit lists, paragraphs, the head of the document, and the body of the document.
One of the elements that may be included in a document written in HTML is a hyperlink or link. A hyperlink enables the user to gain access to another web site by activating the hyperlink. Each hyperlink includes an anchor and a URL. The anchor specifies the text or other content that will be displayed to a user when the hypertext document is displayed on the user""s computer. The anchor may include text or graphics. The URL is a uniform resource locator that specifies the location of the associated web site or Internet resource. An example of a URL is xe2x80x9chttp://www.msn.com.xe2x80x9d
When a hypertext document is rendered on a user""s computer, the hypertext document may include a number of hyperlinks. A user utilizes the hyperlink by positioning a mouse cursor to point within a hot region associated with the anchor and clicking a mouse button. The web browser translates this action into a request to gain access to the resource specified by the URL contained within the hyperlink. In the simplest case, the hyperlink appears to the user as text that is differentiated from other text by being highlighted, boldfaced or distinctly colored. The hyperlink, however, may also appear to the user as a graphical image. The hot region or the hyperlink may encompass the image. In such a case, if the user positions the mouse cursor to point within the hot region and clicks the mouse, the resource associated with the URL contained in the hyperlink will be accessed. In the most complex case, the hyperlink is contained within an image map. An image map is a construct that represents a set of hyperlinks. The image may appears as an image that is segmented into respective hot regions that are associated with respective hyperlinks. Thus, when the user positions the mouse cursor to point inside a given hot region that is part of an image map and clicks the mouse button, the resource identified by the URL for the associated hyperlink is accessed.
One of the difficulties with such hyperlinks is that they are often difficult to discover. Sometimes, the visual cues for delineating hyperlinks within a hypertext document are not very effective. This problem is especially acute with image maps where it is difficult to discern the boundaries of the respective hot regions. Typically, a user is able to identify the presence of hyperlinks by moving the mouse cursor throughout the body of the document and noticing when the mouse cursor changes form. In at least one conventional system, the mouse cursor changes from an arrow to a hand when the hot region of a hyperlink is encountered. One limitation of this approach is that a user must navigate the entire document in order to be certain that he has located each hyperlink within the document. In addition, a user may not know the extent of the hot region and which hyperlink is associated with a given portion of the screen. Furthermore, users who have difficulty using a mouse, such as handicapped users, cannot readily discern the location of the hot regions for the hyperlinks.
In accordance with a first aspect of the present invention, a method of navigating among hyperlinks is performed in a computer system having an output device and a document with hyperlinks. In accordance with this method, the document is displayed on the output device and a tab request is received. In response to receiving the tab request, focus is given to a first of the hyperlinks in the document.
In accordance with another aspect of the present invention,sa hypertext document is displayed on a video display that is part of a computer system. Hyperlinks within the hypertext document are organized into a sequence. When a user depresses a predefined key on an input device, a next one of the hyperlinks in the sequence is given focus.
In accordance with an additional aspect of the present invention, a method is performed in a computer system such that a visual representation of a hyperlink that is part of a hypertext document is displayed on a video display. Focus is given to the hyperlink and a non-rectangular focus shape is drawn around the visual representation of the hyperlink to indicate that the hyperlink has focus. The focus shape may be, for example, a circle or a non-rectangular polygon.
In accordance with a still further aspect of the present invention, an image map is provided at a client from a server. The image map includes multiple hyperlinks. The image map is displayed on a display device at the client. A user presses a selected key on an input device and in response, a visual indication of the presence of a hyperlink in the image map is displayed.
In accordance with another aspect of the present invention, a computer system has a server that downloads a hypertext document to a client computer system.
The client computer system includes a display device on a keyboard. A method is performed such that a hypertext document is displayed on the display device of the client computer system. At least one image of the document is not immediately downloaded but a placeholder for the image is displayed. The user uses the keyboard to indicate that the user does not wish for the image to be downloaded. In response, the system determines that the image should not be downloaded and continues to display the document on the display device. The user may, for example, press a tab key to tab to the placeholder in order to indicate that it does not wish for the image to be downloaded.